An estimated $10 billion in sales to replace 150 maritime surveillance aircraft in the 50,000-lb. category over the next 10 years is leading to intense competition among airframers hungry to “dual-purpose” existing aircraft lines to fill surveillance needs globally. Backfilling for worn out legacy aircraft, including DC-3s and CASA 212s, Fokker F27s, YS-11s and Gulfstream IIIs, is a new generation of medium-class turboprops and business jets converted to maritime surveillance carrying a new generation of smaller sensors that cost less and perform better.

“We are seeing very clearly a move toward cost-effective, multi-mission, special-mission platforms,” says Joar Gronlund, non-executive director at Field Aviation, an aircraft modification company that converted 10 Bombardier Dash 8 Q200s and Q300s to maritime surveillance aircraft (MSA) for the Australian Coast Guard starting in the mid-1990s. “That typically drives you to starting with commercial aircraft. Marry that to an evolution in smaller, lighter and cheaper sensors, and new special-missions platforms are born.”

The action has created what aircraft makers, including Dassault and Bombardier, could see as a burgeoning medium-class MSA niche to supplement a still-sluggish civilian business market. Dassault is offering factory MSA versions of its Falcon 900 and Falcon 2000 business jets; Embraer is offering a maritime patrol version of its ERJ 145 regional jet.

Boeing announced in November that it will partner with Field Aviation to jointly build a business-jet-based MSA that will have mission systems commonality to the larger Boeing P-8A Poseidon, a variant of the 737-800, and a lower cost. The companies are developing an MSA demonstrator using a Challenger 604 and hope to generate the first sales within two years.

The jet offerings will compete head-to-head with turboprops, among them Field's Dash 8 conversions, Airbus's variant of the CN235 regional twin-turboprop, the ATR 42 and 72, and Saab's maritime surveillance and patrol versions of its 340 and 1000 regional turboprops.

With the MSA fleet renewal underway, the trend toward smaller, lower-cost aircraft with similar or better sensor performance is a prime mandate for cash-strapped governments. Based on advances in sensor performance, the same new medium-class MSAs also can perform the jobs of many of the lighter aircraft that had been a part of the legacy surveillance equation, including Cessna 406s and Britten-Norman Islanders.

While jet-powered aircraft are more costly to operate than turboprops in terms of fuel, their benefits come from a faster transit time to more-distant destinations and the ability to climb above weather, capabilities certain customers need.

“In missions with a transit range in the order of up to 300 nautical miles, the best turboprops will generally come up as less costly than the best business jets—particularly when the search criteria of small targets require a relatively low altitude for the surveillance,” says Gronlund. “As the transit distance increases, the jets will naturally fare better.”

Boeing analyzed the maritime surveillance market and determined that a business jet was the best solution to capture a significant portion of the 150 medium-class aircraft it estimates will need to be replaced in the next decade. “Out of that $10 billion, Boeing could capture 25 percent,” says Bob Schoeffling, Boeing Military Aircraft senior manager of business development. Boeing chose the Bombardier Challenger 605 as its platform, and teamed with Field Aviation to perform the modifications. “Not every country in the world wants or needs a P-8,” says Schoeffling. “We looked at how we could offer a P-8-like capability to generate interest in countries that might not need, or be able to afford, the P-8.”

The MSA is part of a broader Boeing MSA and surveillance portfolio that includes the Insitu ScanEagle and Integrator tactical unmanned aerial vehicles on the low end and the P-8 on the high end. The company also is developing a Beechcraft King Air 350-based Enhanced Medium Altitude Reconnaissance and Surveillance System (Emarss) that was flight tested in October.

Schoeffling says the key differentiator setting it apart from competitors in the medium-class MSA market is the U.S. Navy's P-8A tactical open-mission software suite that it will port over to the Challenger 605. The software will manage a variety of sensor options that include a 360-deg. active, electronically scanned array (AESA) radar with synthetic aperture radar, inverse synthetic aperture radar and ground-moving-target indicator modes, a retractable electro-optical/infrared (EO/IR) turret, electronic support measures (ESM), communications intelligence (comint), and an automatic identification system to receive identification information from ships. Boeing is also marketing the aircraft for overland surveillance.

Dassault is advertising similar sensors, with the addition of “underwing carrying capabilities” for sensors or weapons and a self-protection suite. Schoeffling says the future options for the 605 could include a self-protection suite, Link 16 data link for coalition partners, and hard points on the wings, potentially for another sensor or other equipment. “I'm not saying we're going to weaponize it,” he adds.

Field, a risk sharing partner in the program, funded the modifications to the demonstrator aircraft—formerly a Boeing corporate Challenger 604—that arrived at its Toronto facility in February 2013. The modified 604 first flew Feb. 28 and was painted by Boeing at its facilities in Yuma, Ariz., where Field will conduct the remaining flight tests. Boeing will later install mission systems and sensors in Seattle, leading to an international marketing tour later this year. The Challenger 605 is a modernized version of the 604 that Bombardier began delivering in 2007.

Field has some experience with the type, having modified three Challenger 604s to an MSA configuration for the Royal Danish Air Force in the early 2000s. The Danes equipped the Challengers with a low-profile 3.6-meter-long (12-ft.) composite belly pod housing a Telephonics APS-143 imaging radar, and a retractable ball turret with a Flir Systems Star Safire II EO/IR camera mounted behind the belly pod, aft of the aircraft's pressure vessel. The ball turret is retractable to minimize drag at high speeds. One aircraft is equipped with a hard-point to hold an optional side-looking airborne radar (SLAR) or a weapon, and all three have a quick-change interior for executive transport.

Field's mainstay for MSA conversions has come from the Bombardier Dash 8, with nearly 40 conversions of new or used aircraft completed to date for customers that include the coast guards of Australia, Japan, Sweden, Iceland and the U.S. Customs and Border Protection agency. That work continues, although it is becoming increasingly difficult for operators to find good deals on available Q200s and Q300s, the most desirable platforms, as both are out of production and airlines continue to fly them.

The market need for a wider diversity of aircraft prompted the company to “sandwich” the Dash 8 in a standard portfolio that now offers two additional aircraft: the Bombardier Challenger 604/605 on the high end and the Viking Series 400 twin-turboprop, a reincarnation of the DeHavilland Twin Otter, on the low end.

Field partnered with Viking 18 months ago to build a multirole surveillance version of the Twin Otter to be called the Guardian 400, an unpressurized aircraft priced at less than $14 million that the company says will be attractive to “smaller nations.” Modifications, to be completed by Field, will include 360-deg. Selex 5000 search radar for the nose, a retractable EO/IR turret, also on the nose, and additional fuel tanks that boost the maximum takeoff weight to 14,000 lb. from 12,500 lb., giving the aircraft an on-station endurance of 7 hr. for a target 100 nm away. Field is interested in building a demonstrator using Viking's test aircraft, although that aircraft continues to be used for certification testing of a new autopilot, says Gronlund. Instead, the companies are building a nose section with sensors to take to the Farnborough Air Show in July. Viking is primarily marketing the aircraft in the Asia-Pacific region and South America.

The 605 MSA should represent less developmental risk for Field, as the work is similar to the conversions it did for the Danish Challenger 604s. “We're not starting with a white sheet of paper. It's very much an optimization exercise, once the project requirements are defined,” Gronlund says. The new aircraft will mirror the 604 in terms of the retractable EO/IR turret mounted aft of the aircraft's pressure vessel, but it will have a larger belly radome that can fit more than one manufacturer's radar from a menu provided by Boeing, giving operators more flexibility. The pods in the Field's Dash 8 conversions can carry radars built by Elta, Telephonics or Selex, according to Gronlund.

With the larger pod also comes more drag, but Gronlund says the Boeing mission profile is less demanding than that of the Danish. “They had to fly from Copenhagen to Greenland without getting wet in the process,” says Gronlund of the Danish air force mission. “It forced a smaller radome.” Gronlund says the radome and non-retractable EO/IR nose turret on the Dash 8 have a 3% performance penalty for transit and high-speed surveillance, in terms of distance covered per unit of fuel burned, and he expects the Challenger 605 penalty to be “slightly higher” when measured during flight testing this year.

Boeing is designing the aircraft for a basic mission endurance of 8 hr., with 6 hr. on station, a mission efficiency of 75% (on-station time/total time). For a target with a 1,200-nm transit, the 605 can be on station in 2.5 hr. and loiter for another 3 hr., a mission efficiency of 60%. “A prop plane can't do that,” he says. Dassault is marketing similar mission efficiencies for its Falcon 2000. Dassault and Embraer would not comment on MSA orders or deliveries.

For the 605 MSA, Boeing plans to sign the customers and buy green aircraft from Bombardier. Field will perform the structural and aerodynamic modifications over an expected 4-5-month timeframe, a process that is somewhat slowed by the limited number of people able to access the sections of the fuselage where large portions of metal have to be cut out for the sensors, says Brian Love, Field's chief commercial officer. After removing the interiors, the under-floor fuel tank must be removed to install the radome. Along with ESM antennas in the radome and tail, and comint antennas on a platform behind the radome and on the wings, technicians will install wiring and power inverters for the electronics and relocate the lavatory from the back of the plane, where electronics racks are placed, to the front of the cabin. Field is also installing an Inmarsat satellite communications system. From there, Boeing will take the aircraft to install mission systems and sensors as well as painting, all of which Field says should take 2-3 months.

Schoeffling says the baseline crew will be two pilots and three crew members for three workstations, with an option to expand to five workstations. The competitors have similar offerings.

Creature comforts on the 605 will include a kitchen and two of the original cabin seats for crew rest or extra passengers.

On the 604 demonstrator, Field is planning for more than 60 test flights in Yuma to verify acceptable handling and measure performance degradation parameters, due to the sensor drag, ahead of gaining Transport Canada supplemental type certificate approval for the modification, which should equate to an FAA approval through bilateral agreements. Beyond the demonstrator, Boeing plans to install mission systems and sensors at a location in the U.S.—which Field hopes will be its corporate headquarters in Ohio.

Boeing is conducting the flight-test program for the sensors and mission systems.

As for the relatively long window for finding a launch customer, Schoeffling says it is a function of the formalized procurement cycles for governments, which generally include requests for information and proposals as well as competitive bidding. “We are well along the way in conversations with several countries,” he says. “Unfortunately, buying an aircraft is not like buying a car.”

Tap the icon in the digital edition of AW&ST for a look at how civilian bizjet and turboprop makers are competing for a potentially lucrative maritime surveillance replacement aircraft market, or go to AviationWeek.com/video